Understanding the pathogenesis of Mycobacterium intracellulare disease is very important to facilitate uncovering potential drugs active against this disease. Development of animal and macrophage models are the two broad areas of pursuit in the study of the pathogenesis of this disease. Experiments so far completed and thus contemplated to be carried out in the coming year are aimed with these objectives. Thus, the studies using normal and immunesuppressed animals and the phagocytosis and intracellular growth of this organism will help advancement of the knowledge in this area.